It was once the base for a series of domestic terror attacks.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

A line of blue paint marks the route of the inaugural parade.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

An overlooked memorial honoring the local Washington residents who died in World War I.

Look closely and you’ll notice that the color changes a third of the way up the tower.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

A historic arena where the Beatles played their first concert in the U.S.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

Washington's iconic carousel has a nice piece of Civil Rights history.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

The "lovely red Vega" of the legendary record-settling pilot.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

The most accurate timepiece in the world.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.